io 6 Sir William Hamilton's Account of 
the late eruption could not be said to have finished, although 
the force of it was over the 22d of June, since which time the 
crater has been usually visible. The power of attraction in 
mountains is well known ; but whether the attractive power 
of a volcanic mountain be greater than that of any other 
mountain, is a question : all I can say is, that during this last 
eruption every watery cloud has been evidently attracted by 
Vesuvius, and the sudden dissolution of those clouds has left 
such marks of their destructive power on the face of the coun- 
try all round the basis of the volcano as will not soon be erased. 
Since the mouth of Vesuvius has been enlarged, I have seen a 
great cloud passing over it, and which not only was attracted, 
but was sucked in, and disappeared in a moment. 
After every violent eruption of Mount Vesuvius, we read of 
damage done by a mephitic vapour, which coming from under 
the ancient lavas, insinuates itself into low places, such as the 
cellars and wells of the houses situated at the foot of the volcano. 
After the eruption of 17 67 , 1 remember that there were several 
instances, as in this, of people going into their cellars at Portici, 
and other parts of that neighbourhood, having been struck down 
by this vapour, and who would have expired if they had not 
been hastily removed. These occasional vapours, and which 
are called here mofete , are of the same quality as that perma- 
nent one in the Grotta del Cane, near the lake of Agnano, and 
which has been proved to be chiefly fixed air. The vapours, 
that in the volcanic language of this country are called fuma- 
roli, are of another nature, and issue from spots all over the 
fresh, and hot lavas whilst they are cooling ; they are sulphu- 
reous and suffocating, so much so that often the birds that are 
flying over them are overpowered, and fall down dead of 
